A Xorn can use three slam and one bite attacks per round and fight up to three opponents at the same time.

It can use camouflage to blend into stone backgrounds, gaining +5 to hide attempts. In combat, it is more likely to meld into any stone surface, then move and attack from somewhere else 1d3 rounds later, thereby gaining surprise (top of initiative order).

While passing through stone, it can be damaged by a Shatter spell as if it was an inanimate object, and a Transmute Earth spell with a spellcheck result of 20+ on the stone area it passes through will destroy it; a successful lower result will expel it from the stone and turn its body into mud, which prevents it from merging with stone and lowers its AC to 12 for 1d6 rounds while it reforms its structure to stone.

Xorns are immune against any kind of fire and cold and get a Fort save against electrical attacks, negating all damage if successful and taking half damage if failing. They always take only half damage from edged weapons.